Injector for internal combustion engines



F. G. HEHR INJECTOR FOR INTERNAL COMBUSTION ENGINES 2 Sheets-Shet 1 Filed July 18, 1932 INVENTOR BY Hea'eZLcZDG.

ATT RNEY necfzs, 1934. N

2 Sheets-Sheet 2 INVENTOR Frederic/20G. ehr

ldliRN 2Y5 Dec. 25, 1934. F. G. HEHR INJECTOR FOR INTERNAL COMBUSTION ENGINES Filed July 18. 1932 MN 3 Nu Q %7 Z w? N w Patented Dec. 25, 1934 UNITED STATES PATENT OFFICE INJECTOR FOR INTERNAL COMBUSTION ENGINES Application July 18, 1932, Serial No. 623,099

7 Claims.

This invention relates to injectors, and more particularly to fuel injectors for internal combustion engines.

In the art to which the present invention appertains, injectors have been provided designed to supply a definite quantity of the fuel to the combustion chamber of the engine, the fuel being injected in the same manner and with the same v force under all conditions of piston operation, but varying as a result of faulty pump or fuelfeed operation to the injector. The aim of an injector is to distribute a certain quantity of fuel through a certain space in such a manner that the fuel injected is divided evenly into the space covered by the spray. The solution of this problem would be an easy matter if the fuel quantity per injection was at all times uniform. But it varies, first because of varying piston operation in the combustion cylinder, and secondly, because of irregularities of the fuel flow to the injector. Under heavy load upon the piston, it is desirable, if indeed not necessary, to supply a greater amount of fuel to the combustion chamber than in the case of a light load. The greater fuel charge can and should be more widely distributed in the combustion chamber than a lighter charge, and conversely, it is necessary to concentrate a lesser fuel charge in order to obtain maximum efficiency from the fuel.

An object of the present invention is to provide for a variable concentration of the injected fuel; a further object is to automatically vary the concentration as result of the prevailing operating condition; other objects are to concentrate the fuel spray for light load conditions and to diffuse the fuel to greater extent under increased load conditions; to provide a structure readily applicable to the internal combustion engine; to avoid complicated or fragile structures; to secure simplicity of construction; and to-obtain other advantages and results as may be brought out in the following description.

Referring to ,the accompanying drawings, in which like numerals of reference indicate similar parts throughout the several views,

Figure 1 is a longitudinal sectional view of an injector embodying the present invention;

Figure 2 is a. cross-sectional view thereof on line 22 of Fig. 1;

Figure 3 is a sectional view similar to Figure 1 showing the nozzle end of the injector upon increased scale over Fig. 1.

Figure '4 is a longitudinal sectional view of a modified construction of injector; and

Figure 5 is a cross-sectional view on line 5-5 of Fig. 4.

In the specific embodiment of the invention illustrated in said drawings, and directing attention initially to Figures 1 to 3, the reference nu- 5 meral 1 indicates the sleeve or body portion of the injector, to the outer or forward end of which is applied by screws or other suitable means (not shown) a nozzle 2, and within both of which is mounted a plunger 3 coaxial with said parts. It 10 will be understood that the body or sleeve 1 provides a central bore 4, and that the plunger is properly shaped and proportioned so that a considerable length thereof fits the bore of the sleeve and prevents escape of fuel or pressure from the bore at the end thereof away from the nozzle. For convenience, this interfltting portion of the plunger and sleeve will be referred to as the sealed portion thereof. Between this sealed portion and the nozzle, the bore of the sleeve is of 20 greater diameter than the plunger, thereby forming a fuel chamber 5. A lateral opening 6 and supply pipe '7 therein provide a means of introducing fuel to said chamber from an appropriate source of supply, such as a fuel pump (not shown). 1

At the forward end of the sleeve 1, that is, at the end thereof carrying the nozzle, the plunger provides a valve head 8 of greater diameter than the bore so as to rest against the end of said sleeve as a valve seat for closing the bore as re-. quired. This valve head 8 has an area greater than the plunger cross-section at the sealing portion, whereby pressure in the fuel chamber will exert its influence to unseat the valve head from the end of the sleeve and permit flow of fuel at such time. The end of the sleeve may accordingly be considered a primary valve seat for valve invention. 5

Restriction of the fuel passage to the primary valve seat is preferably effected and according to the present showing is accomplished by an annular boss 9 of slightly less diameter than the sleeve bore and on the side of the valve head toward the bore so as to be positioned therein. I

have shown the periphery of this boss somewhat concave, thus forming an annular passagelo, so as to be assured of fuel for the entire periphery of the valve head. 5

The nozzle provides a valve-head chamber 11 of slightly greater diameter than the valve head, thereby affording passage for the fuel to the opposite side thereof from the fuel supply chamber. This valve-head chamber also provides for a limited longitudinal movement of the plunger, the nozzle providing a secondary seat 12 flatwise of the valve-head on the side thereof opposite from the primary seat. This secondary seat is made with a plurality of grooves 13 therein leading from the outer periphery of the seat to the inner edge .of the same. These grooves are of a character non-radial with respect to the plunger, so that the fuel fed along the grooves will be discharged into the central passage 14 of the nozzle with a whirling or rotary motion. This central passage is restricted by means of an end portion or pintle 15 on the plunger, the extreme end of which preferably has a peripheral enlargement 16 thereon located as shown in the discharge or nozzle end of the central discharge passage which opens into the combustion chamber of the engine for obtaining an atomizing effect upon the fuel at the moment of discharge into the combustion chamber of the engine (not shown). This device serves to atomize fuel under low load conditions, that is,- -when the valve head is not fully seated against its secondary seat 12 and will itself produce an atomizing effect uponthe fuel delivered to it and to an extent depending upon the extent of movement'of the head 8 away from the primary valve seat which movement causes said enlargement to move away from its normal position where it is fully entered in the passage 14.

At the opposite end of the sleeve 1 from nozzle 2, the plunger projects and receives a spiral compression spring 1'7 held against displacement by nuts 18, 18 applied to the threaded end of the plunger and adjustable as shown to adjust the opposing action of the spring for securing the automatic regulating action of the valve as described when the fuel is passed through the device in variable amount. By virtue of this compression spring, the valve head 8 is urged toward the primary valve seat, and thus urging of the spring is overcome in variable amount according to the extent or degree of fuel pressure in chamber 5, whereupon the valve head moves toward secondary seat 12 to an extent depending upon said pressure thereby permitting passage of fluid to an amount governed by the position of the valve head as predetermined by the action of the adjusted action of the spring. The pressure in the fuel chamber 5 and position of the valve head and therefore extent of flow to the nozzle is governed by the rate and quantity of fuel supplied by the pump to the chamber and passed through the injector to the delivery nozzle the position of the valve head being determined by the variable action of the spring in opposing the flow.

sage 14 of the nozzle at a high tangential speed,

that is to say, with a very great whirling impetus, and accordingly passes into the cylinder of the engine with great velocity and highly atomized, the fuel thus introduced is spread very consigiera' bly throughout the cylinder or combustion cham ber. In this manner a widespread centrifugal spray of high velocity will result under full load conditions, the sub-division of the fuel as it is delivered into the engine being assisted to a greater or less extent depending upon the position of the valve head and connected atomizing device 16.

Under low load conditions a lesser quantity of fuel per unit of time is drawn through the in-' jector and hence the fuel pressure on the valve tending to move it toward the secondary valve seat is less and the increasing counter-action of the spring opposing such pressure as the valve moves forward holds the head partially off its secondary seat 12 so that the fuel can bypass the grooves by flowing directly to a greater or less extent from chamber 11 to the passage or bore 14 and to an amount depending upon the extent to which the valve is held off its secondary seat as predetermined by the action of the spring opposing the flow tending to seat it. Since under such condition the fuel is not forced to flow wholly through the grooves on the secondary valve seat but is by-passed to a greater or less extent, the centrifugalaction of grooves 13 is lessened and the fuel is passed to the engine combustion chamber in a more concentrated condition, the degree of concentration depending upon the extent to which the valve is held off its seat. Furthermore at such low loads the atomizing of the injected fuel discharged into the engine cylinder from the injector is assisted at the end portion of the pintle as it passes to a greater or less extent from the nozzle by the bore 14 since the clearance between 16 and 14 is less than the clearance between 14 and 15. Thus under low load conditions the fuel will be concentrated into a smaller space inside the engine combustion chamber thereby giving a small zone of hot, intense combustion resulting in' the best utilization of the fuel injected.

Referring now to Figures 4 and 5, there is from an appropriate source, such as a fuel pump (not shown), as previously described. At the juncture of the plunger 22 with head 8, is an annular passage 10 to which the grooves or fiutings communicate. As the nozzle 2, pintle 15 and associated parts, including both primary and secondary valve seats are the same as in the construction first described, further discussion thereof may be omitted. The fuel fed to chamber 25 passes to annular passage 10 by way of flutings 24 and passes around valve head 8 to the nozzle passage 14 in a manner which will be understood from the description previously given.

Other changes and modifications may be made in the construction and use of my improved iniector, without departing from the spirit or scope of the invention, andiI do not wish to be understood as limiting myself to the exact constructions shown and described, except as set forth in the following claims when construed in the light of the prior art.

Having thus described my invention, I claim:-

1. An injector comprising in combination a primary valve seat and a secondary valve seat, said secondary seat being provided with tangential grooves to allow for the passage and direction of fluid, a plunger having a valve head positioned between said valve seats and adapted to seat on either one of said seats and movable therebetween and means acting on said head to hold it partially off said secondary valve seat to provide a bypass of variable extent around said grooves depending upon the position of said head with respect to said secondary valve seat.

2. A fuel injector comprising a body portion and a nozzle, said body portion providing a primary valve seat and said nozzle providing a secondary valve seat having passages for producing a whirling flow of fluid and adapted to permit a by-pass flow independent of said passages and a valve head mounted to move between said seats by the operating pressure of the fluid drawn through the injector and means for causing said head to assume difierent intermediate positions between said seats dependent upon the extent of flow or operating pressure thereby regulating the degree of whirling motion of any fluid passing said seats by allowing more or less cross flow across the secondary seat.

3. An injector comprising a body portion and a nozzle, said body portion providing a primary valve seat and said nozzle providing a secondary valve seat having a tangential groove for passage of fuel and for creating a whirling discharge thereof, and a valve head and pintle mounted to oscillate between said seats in response to operating pressures and to assume intermediate positions between said seats dependent upon the pressure of fuel flow said head when in intermediate positions forming with said secondary valve seat a by-pass for the flow around the groove.

4. An injector comprising a body portion and a nozzle, said'body portion providing a primary valve seat and said nozzle providing a secondary valve seat having a non-radial groove for passage of fuel and for creating a whirling discharge from an otherwise non-whirling discharge, said nozzle having an atomizing discharge passage for receiving said fluid and discharge the same in atomized condition, and a valve head mounted to oscillate between said seats in response to operating pressures and to assume intermediate positions between said seats dependent upon the pressure of fuel flow said head when in intermediate positions forming with said secondary valve seat a by-pass for the flow around the groove.

5. A fuel injector for internal combustion engines comprising a nozzle having a valve seat having a tangential groove therein for passage of fluid and for creating a whirling discharge thereof by said groove under conditions of maximum discharge, said nozzle having an atomizing passage for receiving said fluid, and a valve head for cooperating with said valve seat and having a pintle in said atomizing passage provided with an atomizing attachment moving with the pintle and valve under varying load and located and moving in the discharge end of said passage within the engine cylinder for assisting in the atomization of the fluid both in whirling and nonwhirling condition.

'6. A fuel injector for internal combustion engines comprising a nozzle having a valve seat having a non-radial groove therein for passage of fluid and for creating a whirling discharge thereof, said nozzle having an atomizing discharge passage for receiving said whirling discharge, and a plunger having a valve head for cooperating with said valve seat and having a pintle in said atomizing-passage, the outer end of said pintle having a peripheral enlargement thereon located in the discharge nozzle and moving in said nozzle with the valve head and plunger to position dependent upon the extent of the fuel flow past the valve head seat for assisting in the discharge of the fluid in atomized condition.

7. A fuel injector for internal combustion engines comprising a body portion and a nozzle arranged end to end and having a central bore therethrough, said body portion providing a primary valve seat and said nozzle providing a secondary valve seat, a plunger in said bore having an annular space between it and said bore for providing a fuel chamber, said space being next adjacent to the valve seat end of the body portion and said plunger sealing the opposite end of said body portion, a valve head on said plunger disposed between said seats, the side of said head toward the chamber when resting on its seat sealing the outlet from said chamber and the opposite side of said head acting as a regulating device in cooperation with the secondary seat according to the movement of the valve maintained by said head under the opposing influences of the pressure of fluid delivered to said chamber and drawn through the injector with a pressure dependent upon the load, and of a spring for actuating the valve head contra to the influence of the pressure in said chamber.

FREDERICK G. HEHR. 

